Access control readers, or secure identification readers, are likely to be subject to vandalism or hacking acts consisting in opening the casing, by separating the facade from the base, in order for example to hack the electronics embedded inside of the casing which ensures the detection and the automated opening of a restricted access door.
To guard against such acts, it is known to provide for devices for detecting the opening of the casing, in order for example to emit an alarm and/or to disconnect the reader in order to make it unusable and/or to erase memorized data such as authentication keys.
Conventionally, the detection devices are of the type mechanical switch, generally infrared optical sensor, or magnetic sensor of the flexible-blade switch or reed switch type.
However, these detection devices prove to be easily circumventable, for example by inserting a blade between the facade and the base so as to maintain the contact on the mechanical switch, by inserting a reflecting blade between the facade and the base and in front of the optical sensor in order to form a decoy simulating the closed configuration of the casing, or by positioning a magnet proximate to the magnetic sensor in order to also simulate the closed configuration of the casing.
Furthermore, the detection device with a mechanical switch has other drawbacks, such as the wear of the parts, the complexity and the fragility of the mounting when closing the casing. The detection device with an optical sensor is, in turn, very energy-consuming, not to mention the complexity of the mounting which requires centering an element in front of the sensor. The detection device with a magnetic sensor is also complex to be mounted because it also requires centering a magnet in front of the sensor.
Finally, these detection devices are not able to detect a complete pull-off of the casing, facade and base included, in other words, a removal of the casing from his wall support without opening the casing, because the (mechanical, optical or magnetic) sensor is always comprised between the base and the facade.
It is also known from the document US 2011/0054830 to provide for a motion detection device integrating an accelerometer, this detection device being placed on existing objects (flap of a printer, door of an enclosure, tab of a box, . . . ), without suggesting any modification of the structure or the kinematics of the object. Although this detection device is interesting, it is however not enough to just directly place such a detection device, in order to address the problem of risk of falsification.